Surface acoustic wave device, electronic component using the device, and composite module
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsMitsuhiro Furukawa, Kiyoharu Yamashita, Hiroshi Kurotake, Hiroyoshi Sekiguchi
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Abstract
A surface acoustic wave device includes a piezoelectric substrate and an electrode provided on the substrate. The electrode includes a first metal layer provided on the piezoelectric substrate and having a trapezoid shape in the cross section and a second metal layer provided over the piezoelectric substrate at the same position as the first metal layer over the piezoelectric substrate. By controlling the shape of side surfaces of the electrode, the surface acoustic wave device hardly vary in a propagation frequency.
Claims57
A surface acoustic wave device comprising:
- a piezoelectric substrate;
- and
- an electrode including
- a first metal layer provided on said piezoelectric substrate and having a trapezoid shape in a cross section, and
- a second metal layer provided over said piezoelectric substrate at a same position as said first metal layer.
A surface acoustic wave device comprising:
- a piezoelectric substrate;
- and
- an electrode including
- a first metal layer provided over said piezoelectric substrate and having a cross section of a rectangular shape, and
- a second metal layer provided over said first metal layer and being wider than said first metal layer.
A surface acoustic wave device comprising:
- a piezoelectric substrate;
- an electrode provided on said piezoelectric substrate and having a projection provided on a side surface thereof;
- and
- a protective layer for covering at least an upper surface and said side surface of said electrode.
Dependencies are inferred from the claim text.